1. Field of the Invention
This invention relates to deadbolt and similar lock assemblies. More particularly, this invention relates to a deadbolt assembly incorporating an improved means of lock cylinder retention within the assembly and means for facilitating one of two different deadbolt extensions during manufacture of the lock assembly.
2. Description of the Prior Art
A typical deadbolt lock unit incorporates exterior and interior housings, within which are carried lock cylinders. Each of the lock cylinders includes a driver bar which extends from the rear thereof. The driver bar is coupled to a deadbolt assembly located between the interior and exterior housings. Rotation of the driver bar causes extension or retraction of the lock bolt. Prior art lock devices of this type are disclosed in U.S. Pat. Nos. 4,073,172 to Schlage, 3,768,284 to Kent, et al., and 3,628,356 to Deahl. Many lock assemblies incorporate a drill resistant cap which extends through an opening in the housing and covers the lock cylinder so as to protect it against tampering. The cap includes an opening which exposes the keyway of the lock cylinder. In addition to the above patents, such caps are disclosed in U.S. Pat. Nos. 1,488,925 to Hurd, 1,411,898 to Augenbraun, RE16,123 to Schonwald and 2,126,291 to Jacobi.
Generally, the lock cylinder assembly is positioned within a bore within the housing, and some type of securement device is required to keep the lock cylinder both axially and longitudinally aligned. In the Schlage patent, a separate retaining ring utilized hold the cylinder cap at the front of the housing and a loop support surrounds the rear of the cylinder and is attached to the housing. Although the loop support provides adequate retention and alignment of the lock cylinder, it increases the difficulty of assembly since the loop must be passed around the rear of the lock cylinder.
Another problem which has been addressed in the present invention concerns the degree of deadbolt extension which is available with a particular lock unit. Typically, the coupling mechanism between the driver bar of the lock cylinder and the lock bolt is designed so that the lock bolt will extend a predetermined fixed amount each time the deadbolt unit is locked. Different degrees of extension are used for different applications, however, with 1" and 5/8" extensions being typical. When the deadbolt unit is unlocked, the lockbolt retracts so that it fits flush with a strikeplate. The amount of extension is controlled by the design of the coupling mechanism, and has generally required a different design to accomplish different degrees of extension.